Commit 0d830032 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Daniel Borkmann
Browse files

bpf: xdp: allow offloads to store into rx_queue_index 



It's fairly easy for offloaded XDP programs to select the RX queue
packets go to.  We need a way of expressing this in the software.
Allow write to the rx_queue_index field of struct xdp_md for
device-bound programs.

Skip convert_ctx_access callback entirely for offloads.

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent a1d1f079

include/linux/bpf.h

+1 −1
Original line number Diff line number Diff line
@@ -627,7 +627,7 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map); 
#if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)

int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr);



static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux)

static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux)

{

	return aux->offload_requested;

}

kernel/bpf/verifier.c

+1 −1
Original line number Diff line number Diff line
@@ -5215,7 +5215,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) 
		}

	}



	if (!ops->convert_ctx_access)

	if (!ops->convert_ctx_access || bpf_prog_is_dev_bound(env->prog->aux))

		return 0;



	insn = env->prog->insnsi + delta;

net/core/filter.c

+8 −1
Original line number Diff line number Diff line
@@ -4645,8 +4645,15 @@ static bool xdp_is_valid_access(int off, int size, 
				const struct bpf_prog *prog,

				struct bpf_insn_access_aux *info)

{

	if (type == BPF_WRITE)

	if (type == BPF_WRITE) {

		if (bpf_prog_is_dev_bound(prog->aux)) {

			switch (off) {

			case offsetof(struct xdp_md, rx_queue_index):

				return __is_valid_xdp_access(off, size);

			}

		}

		return false;

	}



	switch (off) {

	case offsetof(struct xdp_md, data):

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